Checkweigher reject mechanism



Jan. 26, 1965 A. D. HARMON ETAL 3,167,171

CHECKWEIGHER REJECT MECHANISM Filed Sept. 3. 1963 2 Sheets-sheaf 1 -4- \a a I 1 g T I INVENTORS Alberi D. Harmon Claude E. Mansees ATTORNEYS Jan. 26, 1965 A. D. HARMON ETAL 3,167,171

CHECKWEIGHER REJECT MECHANISM 2 Sheets-Sheet 2 Filed Sept. 55, 1963 4 y M RQN N "v 253mm 72:21.: iw

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EE EE INVENTORS AZber-Z D. Harmon CZaude E. 1140725665 ATTORNEYS United States Patent M 3,167,171 CHECKWEIGHER REIECT MECHANISM Albert D. Harmon and (Zia-ride E. Monsees, Durham,

N .C., assignors to Sperry Rand Corporation, Wilmington, Del, a corporation of Delaware Filed Sept. 3, 1963, Ser. No. 306,251 14 Claims. (Cl. 198-41) This invention relates to a device for separating under- Weight and overweight packages or articles from packages or articles of correct weight as they leave a check- Weighing machine.

It is common practice in the packaging arts to finally check-weigh each package or product after it has been processed to insure that all those finally delivered are within a certain range of correct weight. Such checkweighing machines conventionally determine the weight of each package or product passing therethrough and produces a signal indicating whether a particular package is underweight or overweight. It is further conventional to employ some memory system or otherwise to condition a further mechanism to actually separate the underweight and overweight packages from the others. It has been known to employ a conveyor consisting of transverse rods on which article carriers are slidably mounted. As a row of packages leaves a check-weighing machine, a signal is delivered to the reject mechanism at the time a particular package reaches the same, indicating whether that package is to be rejected and withdrawn as being underweight or overweight. Conventionally, the signal operates a deflecting mechanism of some sort to push the package of improper weight out of an advancing row of packages, to one side or the other thereof, depending upon whether it is underweight or overweight. All such prior mechanisms involve moving parts subject to jamming and other difficulties, whereas the present invention avoids the use of all moving parts.

According to the present invention, a reject mechanism comprises a conveyor having transverse guide rods on which article carriers are slidably mounted and each carrier is provided with a roller of ferro-magnetic material. At the entrance end of the conveyor, all the carriers are forced to a central position to pass between the poles of opposing electromagnets. As a particular package carrier reaches the space between the electromagnets, the signal from the checkweigher is delivered thereto and if that particular package is underweight or overweight, the appropriate electromagnet is energized to attract the electromagnetic part of the carrier and deflect the carrier along the rods and thereby displace he package to one side of a central path and into engagement with a diagonally extended elongated permanent magnet. The electromagnet is then de-energized and the roller continues to follow the permanent magnet as it advances to further displace the carrier away from the central part of the conveyor. Thus, the articles delivered from the check- Weigher passes centrally along the reject mechanism if they are of correct weight, but are deflected to one side or the other if they are of incorrect weight.

It is, therefore, an object of this invention to provide a reject mechanism of the type described employing no moving parts and thus being free of all danger of jamming.

Another object is to provide a reject mechanism as set forth which is capable of operation in combination with any checkweighing mechanism.

Still another object of the invention is to provide a reject mechanism of the type described which is simple and economical to construct and eflicient and reliable in operation.

A further object is to provide a reject mechanism for 3,lti7,l?l Patented Jan. 26, 1955 deflecting articles of improper weight and which employs no moving parts but functions solely by magnetic forces.

Additional and further objects and advantages will become apparent to those skilled in the art as the description proceeds ith reference to the accompanying drawings, wherein:

FIG. 1 is a plan view of a reject mechanism embodying the present invention;

FIG. 2 is a side view of the mechanism of FIG. 1 with portions thereof being broken away;

FIG. 3 is a vertical sectional view taken along the line 3-3 of FIG. 1; and

FIG. 4 is a vertical sectional view taken along the line 4--4 of FIG. 1.

The mechanism shown in the drawings consists of. an endless conveyor comprising side chains 2, each being supported and guided on suitable guide means 4 on a framework 6. The chains 2 are transversely spaced and the pivot pins thereof are elongated to define spaced parallel transverse guide rods 8. Each of the chains 2 is trained over a driven sprocket 10 and an idler sprocket 12 at respectively, entrance and discharge ends of the conveyor. The sprockets 10 are fixedly mounted on a transverse shaft 14 to which drive sprocket 16 is secured. The drive sprocket 16 is driven through a chain 18 by a motor 20 or the like. Obviously, the shaft 14 could be driven from any other suitable power source, for example, a shaft on the checkweighing machine with which the present mechanism may be associated.

Adjacent pairs of transverse rods 8 .slidably support article carriers 22. Each article carrier consists of a support plate 24 (FIG. 4), end members 26 and a bot tom plate 28. The end members 26 are provided with aligned openings slidably receiving adjacent rods 8 and the upper plate 24 provides a supporting surface for packages or products or other articles. The bottom plates 28 each have journalled centrally thereon a roller 30 formed of ferro-magnetic material whereby it will be magnetically attracted to a permanent magnet or electromagnet. The framework 6 of the conveyor includes a horizontal partition member 32 (FIGS. 3 and 4) midway between the upper and lower runs of the endless conveyor. Fixed to the lower surface of the partition 32 are suitable supporting members 34 supporting elongated cam elements 36 adjacent the lower run of the conveyor. As best seen in FIG. 1, the cam elements 36 extend from the lateral extremities of the conveyor at the discharge end thereof and converge inwardly toward each other at the entrance end of the conveyor. At the entrance end, the cam members 36 are curved upwardly and rearwardly concentric to the shaft 14 and are maintained in spaced relation to the runs of the conveyor such that they are at the same elevation as the rollers 30 on those carriers 22 returning along the lower run. Obviously, irrespective of the lateral displacement of any carrier on the rods 8, when it returns along the lower run of the conveyor, the cam elements 36 will engage its roller 30 and thus force the carrier to the central part of the endless conveyor to the position shown at the left end of FIG. 1.

The partition 32 is also provided with suitable spacing and/ or supporting means 38 to support permanent magnetic members 40 adjacent, but below, the upper run of the endless conveyor. As best seen in FIG. 1, the permanent magnetic members 40 are elongated and are provided with inner opposed edges converging from adjacent the lateral extremities of the conveyor at the discharge end thereof toward a central region of the conveyor near but spaced from the receiving end thereof. Each of the permanent magnetic devices consists of an upper pole plate 41 (FIG. 4) and a lower pole plate 42 with a plurality of permanent magnets 44 therebetween. The magnets 44 are so magnetized and oriented that one of the pole plates constitutes. a north pole and the other constitutes a south pole. Thus, when the ferromagnetic roller of any article carrier 22 is moved laterally to engage the inner edge of either permanent magnetic device 40, it will be attracted by the same and held thereto even during its advance movement with the endless conveyor. It is to be noted that the pole plates 41 and 42 and the rollers 30 are so related and dimensioned that each roller will extend across the edges of both pole plates to complete a circuit for the magnetic flux and thus achieve maximum attraction between the parts.

The permanent magnet devices 49 terminate in forward ends 46 (FIG. 1) spaced some distance from the left end of the endless conveyor. A pair of electromagnet devices are arranged on opposite sides of the central region of the endles conveyor and preferably comprise upper and lower pole plates 48 substantially coplanar with the pole plates 41 and 42. Electromagnetic coils 50 are arranged between the pole plate 48 and may be respectively connected to the means delivering signals from the checkweigher so as to be energized in accord ance with the signal received. The inner or opposed edges of the pole plates 43 are configured to be generally parallel at the entrance end of the endless conveyor and to curve or otherwise diverge outwardly therefrom to define a path constituting a continuation of the inner edges of the permanent magnetic members 40. However, there is a gap (as illustrated) between adjacent ends of the pole plates 48 and the permanent magnet members 40. It is to be further noted that the inner ends of the permanent magnet members are spaced apart transversely of the endless conveyor a suflicient dis tance so that an article carrier 22 centrally positioned on the rod 8 will pass therebetween without being attracted by either sufliciently to be moved thereto. In other words, in the absence of an additional force, the permanent magnet devices 40, in and of, themselves cannot draw or deflect article carriers 22 from their central position on the endless conveyor.

As will be obvious from the structure thus described, articles being delivered by a checkweigher, on conveyor 52, for example, are successively deposited on article carriers 22 on the reject mechanism and signals generated by the checkweigher mechanism are delivered, through appropriate amplifiers, relays or the like, to the appropriate electromagnetic coils 50. For example, if the checkweigher detects a package that is underweight, the resulting signal will be applied to the upper or left-hand coils at the time that package, and its carrier, reaches a position between the electromagnetic devices and such signal causes a current to flow through the coils 50 and thereby magnetize pole plates 4% to draw the roller therebetween over to that pair of pole plates and to hold it there as the carrier advances with the endless conveyor. The roller 30 rolls along the inner edge of the pole plates 4% and rolls therefrom onto the inner edge of the associated permanent magnet device 4ft and is then carried by the endless conveyor to a laterally displaced position as illustrated, for example, at A in FIG. 1. If the article reaching the reject mechanism is overweight, the signal from the checkweigher is applied to the lower or right-hand coils St) to thus deflect the overweight packages to the right and carry them to the opposite lateral position indicated at B in FIG. 1. Thus, the mechanism described can separate underweight packages and overweight packages from packages of correct weight by forming three different rows thereof as they are delivered from the delivery end of the endless conveyor onto take-away conveyor 54.

As shown in the drawings, the inner edges of the electromagnetic pole plates 48 are of substantial length and more than one of the rollers 30 is between them at any given time. However, the signal can be so timed to the operation of the mechanism that the signal corresponding to the carrier shown at C in FIG. 1 continues until the carrier reaches the position C. Even though energization of the electromagnet will attract the next following roller (and perhaps even two following rollers) yet termination of the signal when the carrier reaches the position C will leave the other attracted rollers still located centrally of the endless conveyor and thereby subject to subsequent signals only. If the signal corresponding to the carrier at position C is terminated, the next following roller is still so near the center of the endless conveyor at the time the signal is terminated that it will pass the adjacent end of the permanent magnet members 40 sufliciently far therefrom so as to pass therebetween without being deflected.

While a single specific embodiment of the invention has been shown and described herein, it is to be understood that the same is merely illustrative of the principles involved and that the invention may embody other forms falling within the scope of the appended claims.

We claim:

1. A reject mechanism comprising: a conveyor movable along a predetermined path; a plurality of article carriers supported by said conveyor for independent movement thereon transversely of said path; each carrier having a fcrro-magnetic portion; a permanent magnet device fixed adjacent said conveyor and having at least one elongated pole face arranged to extend from a central region of said conveyor in outwardly diverging relation in the direction of movement of said conveyor; said pole face being arranged to be engageable by said ferro-magnetic portions of said article carriers; and selectively operable means for deflecting selected ones of said carriers laterally on said conveyor to engage their ferro-magnetic portions with said pole face.

2. A reject mechanism comprising: a conveyor movable along a predetermined path; a plurality of article carriers supported by said conveyor for independent movement thereon transversely of said path; each carrier having a ferro-magnetic portion; a pair of permanent magnet devices fixed adjacent said conveyor and each having at least one elongated pole face arranged to extend from laterally spaced inner ends thereof at a central region of said conveyor in outwardly diverging relation in the direction of movement of said conveyor; said pole faces being arranged to be engageable by said ferro-rnagnetic portions of said article carriers; and selectively operable means for deflecting selected ones of said carriers laterally on said conveyor to engage their ferro-magnetic portions with a selected one of said pole faces.

3. A mechanism as defined in claim 2 including means for directing all said carriers approaching said spaced ends to a lateral position on said conveyor such that their ferro-magnetic portions pass between said spaced ends; said portions being so dimensioned as to pass between said spaced ends and spaced from each sufficiently far so as not to be magnetically drawn to either in the absence of actuation of said selectively operable means.

4. A mechanism as defined in claim 2 wherein said selectively operable means comprise a pair of independently energizable electromagnets arranged on opposite sides of said central region adjacent said spaced ends.

5. A mechanism as defined in claim 4 wherein said electromagnets are each provided with a pole face, engageable by said ferromagnetic portions, and defining a guide surface constituting a continuation of said elongated pole face of a corresponding one of said permanent magnet devices.

' 6. A mechanism as defined in claim 2 wherein each journalled on its respective carrier.

7. A mechanism as defined in claim 6 wherein each of said permanent magnet devices is provided with a pair of said elongated pole faces, spaced apart, parallel and defining opposite magnetic poles; said permanent magnet devices and said rollers being so related that said rollers may simultaneously engage both said pole faces to roll therealong.

8. A reject mechanism comprising: an endless conveyor having upper and lower runs; said conveyor comprising spaced, parallel, transverse guide members; a plurality of article carriers slidably mounted on said guide members for supporting articles above said upper run and transporting said articles from one end of said conveyor to the other; a ferro-magnetic follower on each carrier, extending inwardly between said guide members into the space between said runs; means for positioning all said ferromagnetic followers centrally of said conveyor at said one end thereof; selectively operable electro-magnetic means between said runs and adjacent said one end for attracting any selected follower to displace the same and its carrier laterally of said conveyor in either direction; and guiding means for engaging a displaced follower and further moving said follower and its carrier toward a lateral extremity of said conveyor as said carrier moves toward said other end.

9. A mechanism as defined in claim 8 wherein said guiding means comprise pole faces of permanent magnet means and wherein said followers comprise rollers journalled on said carriers and rollable along said pole faces.

10. A mechanism as defined in claim 8 including a fixed partition member between said runs; said means for positioning said followers centrally of said conveyor comprising cams fixed to the underside of said partition and having cam edges adjacent said lower run converging from the lateral edges of said conveyor at said other end toward the central region of said conveyor at said one end; said electromagnetic means and said guiding means being fixed to the upper side of said partition adja cent said upper run.

11. A mechanism as defined in claim 10 wherein said electromagnetic means and said guide means comprise ferro-rnagnetic members having opposed edge faces defining laterally spaced paths respectively extending from a side of the central region of said conveyor at said one end diagonally toward the lateral edge of said conveyor at the other end; the portions of said ferro-magnetic members adjacent said one end being separate elements, and electromagnet coils for selectively magnetizing the portion thereof on either side of said central region; the remainder of said ferro-magnetic members comprising poles of permanent magnets.

12. A reject mechanism comprising: a conveyor movable along a predetermined path; a plurality of article carriers supported by said conveyor for independent movement thereon transversely of said path; each carrier comprising a ferro-magnetic portion; a pair of guiding devices fixed adjacent said conveyor and each having a guiding surface arranged to extend from laterally spaced inner ends thereof at a central region of said conveyor in outwardly diverging relation in the direction of movement of said conveyor; said guiding surfaces being arranged to be engageable by said article carriers; and selectively operable electromagnetic means for deflecting selected ones of said carriers laterally on said conveyor, by attracting their ferro-magnetic portions to displace said carriers into engagement with a selected one of said guiding devices.

13. A mechanism as defined in claim 12 wherein each of said ferro-magnetic portions is in the form of a roller journalled on its respective carrier, said rollers being engageable by said guiding devices to be guided thereby.

14. A mechanism as defined in claim 13 wherein each of said electromagnetic means is provided with a pair of elongated pole faces, spaced apart, parallel and defining opposite magnetic poles; said pole faces and said rollers being so related that said rollers may simultaneously engage both said pole faces to roll therealong; said pole 11/61 Seabom 209121 6/63 Worcester 209--121 SAMUEL F. COLEMAN, Primary Examiner. 

1. A REJECT MECHANISM COMPRISING: A CONVEYOR MOVABLE ALONG A PREDETERMINED PATH; A PLURALITY OF ARTICLE CARRIERS SUPPORTED BY SAID CONVEYOR FOR INDEPENDENT MOVEMENT THEREON TRANVERSELY OF SAID PATH; EACH CARRIER HAVING A FERRO-MAGNETIC PORTION; A PERMANENT MAGNET DEVICE FIXED ADJACENT SAID CONVEYOR AND HAVING AT LEAST ONE ELONGATED POLE FACE ARRANGED TO EXTEND FROM A CENTRAL REGION OF SAID CONVEYOR IN OUTWARDLY DIVERGING RELATION IN THE DIRECTION OF MOVEMENT OF SAID CONVEYORF SAID POLE FACE BEING ARRANGED TO BE ENGAGEABLE BY SAID FERRO-MAGNETIC PORTIONS OF SAID ARTRICLE CARRIERS; AND SELECTIVELY OPERABLE MEANS FOR DEFLECTING SELECTED ONES OF SAID CARRIERS LATERALLY ON SAID CONVEYOR TO ENGAGE THEIR FERRO-MAGNETIC PORTIONS WITH SAID POLE FACE. 